Updated my server to 1.13 just 2 days ago.  When I logged in noticed various areas of my rail system were missing.  Went out and started fixing them.  Then hit a large area that wasn't showing.  Talked on IIRC :  Removed other conversations:

 
09:41 <Ordate> I just updated my personal server to 1.13. While looking what had been goofed I came across a 5 area chunk that is not loading. one in each cardinal direction and the center. Ive restarted the server, changed render distance on the client and nothing seems to be helping. Help?
09:42 <@Odysseius> Ordate, Could you show us a screenshot of the area not loading?
09:43 <Ordate> sure give me a min, takes a bit so that the whole chunk strip doesnt disappear
09:43 <@Odysseius> Ordate, Is it always the same place, and does it always fail to load?
09:43 <Ordate> same place
09:43 <Ordate> and yes
09:46 <Ordate> sec looking to see how to send a screenshot
09:46 <Greymagic27> @Ordate, http://imgur.com
09:54 <Ordate> https://imgur.com/jSYQPkK
09:55 <@Odysseius> Ordate, Can you see those chunks when you open the world in Singleplayer?
09:55 <Ordate> haven't tried. Let me get the world
 
10:08 <Ordate> Same thing is single player
10:09 <Ordate> aka that area is missing
10:11 <Ordate> https://imgur.com/dgM9N2Z from single player
 
 
10:36 <Ordate> is my problem a heck if we know
 
10:39 <@Odysseius> Ordate, Have you ever used any third party tool on the world?
10:40 <@Odysseius> Ordate, Also, what happens if you try to walk into the chunks?
10:40 <Ordate> No always pure vanilla
10:40 <Ordate> whole world disappears
10:40 <@Odysseius> ??> Ordate launcher/log
10:40 <@Absol> Ordate: Please follow the instructions on this page: http://hopper.minecraft.net/help/guides/minecraft-logs/
10:41 <@Odysseius> Ordate, Please copy the log after opening the world and being in the affected area in Singleplayer.
 
10:48 <Ordate> https://paste.ubuntu.com/p/6NydvxNZDm/
 
10:50 <@Odysseius> Ordate, Seems like it's a corruption issue with the world files, usually caused by abrupt crashing while the files are in use.
 
Problem is there hasn't been a crash of the server since I updated.  Kind of at wits end what to do with this.